Tag Archives: electron

PORTLAND, Oregon — Scientists trying to fulfill the 80-year-old dream of Nobel laureate Eugene Wigner, recently discovered how to place crystalline lattices of pure electrons in the bottom of a silicon-encased quantum well. The resulting material promises electron mobility more than 200 times greater than that of graphene and more than 1,700 times that of crystalline silicon.

So far, the work is still at the level of fundamental physics, but if researchers make the kind of advances they anticipate they could open a door to significant applications in semiconductors.

Researchers experimenting with the properties of Graphene have discovered that when the single-atom-thick sheet is exposed to extreme low temperatures and high magnetic field it has the ability to filter electrons according to their spin direction.

At room temperature and with no magnetic field the flake of graphene functions as a normal conductor with electrons flowing throughout the sheet. With the application of a magnetic field perpendicular to the sheet the electrons migrate out to the sheet edges while the rest of the sheet has the properties of an insulator. Current flow around the edges is either clockwise or anticlockwise depending on the orientation of the field (known as the quantum Hall effect).

When the MIT researchers switched a second magnetic field in the same plane as the Graphene sheet they found that electrons move around the edge in either clockwise or counterclockwise direction depending on the electron’s direction of spin. [via]

When we last checked in on Ben Krasnow’s homemade SEM, he had just achieved his first successful image with the device. As his latest video shows, the project has come a long way since then. It’s a long clip, by internet standards, at almost 10 minutes, but Ben does a great job of communicating what he’s doing and why, taking us through each step in the imaging process, from loading the sample, through pumping down the vacuum chamber and powering up the electronics, to fine-tuning the image itself. Which looks great, by the way–even after making the trip to Maker Faire and back.

This is only the most recent in a series of truly outstanding projects from Ben. Check out the links below for some of our past coverage of his work, and Ben’s personal blog for new updates.

The experiment, which spanned more than a decade, suggests that the electron differs from being perfectly round by less than 0.000000000000000000000000001 cm. This means that if the electron were magnified to the size of the solar system, it would still appear spherical to within the width of a human hair.

Today, I finally produced an image with my DIY scanning electron microscope. I’ve spent the last few months working on this project, and am encouraged by today’s success. There is still a lot of work left to do in making the image higher resolution, and eliminating sources of noise, however this image proves that all parts of the microscope are operating as designed.